Alloy



Patented Mar. 3, 1925.

UNITED "STATES A 1,528,478 PATENT OFFIGE.

ROBERT ABBOTT HADFIELD, OF WESTMINSTER, ENGLAND.

ALLOY.

No Drawing.

To all 'wkom it may concern:

Be it known that I, Sir ROBERT Anno'rr HADFIELD, a subject of the King of Great Britain and Ireland, residing at Westminster, England, have invented Improvements in or Relating to Alloys, of which the following is a specification.

. This invention has reference to alloys possessing, in addition to other advantageous characteristi'cs,'that of offering considerable resistance to\ oxidation and scaling'at high temperatures, and to attack by flame and hot' products of combustion, as for instance such as are produced in internal combustion engines. Alloys for this purpose have heretofore been produced comprising in addition to iron, varying percentages of carbon, silicon and chromium, or of carbon, chromium and nickel, or of carbon, chromium, nickel and tungsten, with or without addition, in some cases, of other elements such as manganese, cobalt, molyb denum, vanadium, titanium or copper, or

.of two or more of these elements. The

production of material cap-able of effectively resisting oxidation, scaling and corrosion at high temperature, say for instance up to 10009 C. and above, and which shall at the same time possess good mechanical characteristics including high tensile and compres- 'sion strength, is now becoming of greatly increasing importance for use in internal combustion engines, gas turbines, and for.

other purposes.

The present mvention has for'its object tovarying percentages, varying percentages of 'tungsten, or in addition to iron, carbonchromium and tungsten, or to iron, carbon,

chromium, nickel and tungsten, or to iron, carbon, manganese, chromium, nickel and tungsten, varying percentages of silicon.

In an iron carbon, silicon, chromium, tungsten, alloy according to the lnventlon,

silicon,

Application filed December 16, 1924. Serial No. 756,324.

the percenta eof carbon may vary up toabout 3.5%, the percentage of silicon above 1.3 up to 8%, the percentage of chromium above 8 up to 40% and the percentage of 0 tungsten fro-m about 1 to 10%. In an iron, carbon, silicon, chromium, nickel, tungsten alloy' according to the invention, theeartion; silicon, chromium and tungsten may var within the limits mentioned whilst the percentage of nickel may vary from about 20 up to The percentage of manganese, when managanese is used, may vary from about .5 up to 10%.

It has been found that by forming alloys of the kind hereinbefore referred to, so that they contain in' all cases in addition to iron, carbon, chromium, or to. iron, car.- bon, chromium and nickel, or iron, carbon, chromium, nickel and manganese, within the limits set forth, both silicon and tungsten within the 'limits set forth, such alloys oifer very considerable resistance to oxidation, scaling and corrosion at high temperatures, and also considerable resistance to corrosion at ordinary temperatures, whilst at the same time possessing good. mechanical qualities.

An alloy has been found by experiment to give very satisfactory results, when subjected to scaling tests by heating to about 1000 C. for three hours, contained, in addition to iron, about .45% carbon, about 1.60% about 1.25% manganese, about 13. 70% chrominum, about 26.6% nickel and about-2.90% tungsten.

Another alloy that has been found by experiment to give satisfactory results, contained in addition to iron, about .05% carbon, about 2.73% silicon, about 18.96% chromium, about 06% nickel and about 2.85% tungsten.

According to another example, the alloy may contain in addition to iron, about .35 to 45% carbon, about 3 to 3.5% silicon, about 14{% chromium, about 28% nickel and about 4% tungsten, with, it may be, say about 1.5% manganese.

In alloys of the kind referred to, the tungsten may be replaced in whole or in part by .its equivalent, as for instance by molybdenum, and this substitution is to be understood ascovered by the term tungsten in the appended claims.

Alloys acaording to the present invention possess the good mechanical qualities here- -inbefore referred to when used either at high temperatures or at ordinary tempera:-

tures, as well as offering great resistance to oxldatlon, scaling and corrosion at high temperatures and great resistance to corrosion by chemical action, .as for instance that of ordinary acids, fresh water and sea Water and so forth at ordinary temperatures. 1

Other elements, such as cobalt, vanadium,

' of the kind hereinbefore described, is found to improve its non-corrodible character at high and ordinary temperatures and also when exposed to the action of air, fresh Water and sea water at ordinary temperatures. For instance, an alloy comprising, in addition to iron, about .59% of carbon,

about 1.45% of silicon, about 1.57% manganese, about 14.7% of chromium, about 27.9% of nickel, about 3.61% tungsten and about 2.20% of copper has been found to possess good non-corrodible qualities in ad dition to good mechanical qualities.

What I claim is 1. An alloy having as its principal ingredients, iron, and chromium, or, iron, chromium and nickel, the chromium content or combined chromium and nickel content being about 19 to 42%, with the chromium approximately 13% or above, together with SllICOIl 1.3 up to 8% and substantially above 1% and up to 10% of tungsten,-said alloy being capable of offering considerable resistance to oxidizing, scaling and corrosion at high temperatures.

2. A: ferro-chrome-nickel alloy having a combined chromium nickel content 015 about from 19 to 42%, with the chromium approximately 13% or above, together with silicon 1.3 up to 8% and from substantially above 1% and up to 10% tungsten.

3. An alloy having as its principal ingredients, iron, chromium and nickel, the chromium content being about 13.70%, the nickel content about 26.06% and containing carbon about .45, silicon. about 1.60 and tungsten about 2.90%.

Signed at London, England this third.

day of December 1924.

ROBERT ABBOTT HADFIELD. 

